1. Field of the Invention
This invention relates to a novel loudspeaker sound collecting and concentrating tube or tubes that are attached to or are integral with the back of a conventional speaker frame for capturing sound emitting from the back of the loudspeaker.
2. Description of the Prior Art
In the prior inventions, attempts have been made to improve the efficiency of loudspeaker systems and while at the same time to accurately reproduce high-fidelity sound. Specifically, attempts have been made in two areas of the loudspeaker system: improvement in loudspeaker cone and diaphragm material, utilizing modern technology and improvement in the housing to reduce unwanted vibrations within a loudspeaker housing.
A loudspeaker system utilizing or manipulating sound waves emitting from the rear or back of the loudspeaker has been proposed, for example, in U.S. Pat. Nos. 4,439,644 to Bruney, III, 4,524,846 to Whitby, 4,655,315 to Saville, 4,807,293 to Weckler, and 4,930,596 to Saiki et al.
In U.S. Pat. No. 4,439,644 to Bruney, III, a loudspeaker system utilizes a plurality of vinyl sheets having different thicknesses to seal the rear of a speaker housing, to relieve pressure behind the loudspeaker driver, and to attenuate sound waves emitted from the back of the speaker. While this type of system minimizes the housing vibration and generation of the spring-like compression effect or the resonant booming effect often associated with an acoustic suspension enclosure, the speaker is not as efficient as a ported speaker system in general. Unlike the prior inventions, the present invention collects sound waves emitted from the rear of a loudspeaker and directs the collected sound waves to a single sound concentrating horn and the like. The sound waves emitted from the back of a loudspeaker do not disperse nor are absorbed by the speaker housing.
In U.S. Pat. Nos. 4,524,846 to Whitby and 4,807,293 to Weckler, a loudspeaker system directs sound waves emitted from the back of a loudspeaker through a convoluted path formed by baffles formed within the housing. This type is known to provide a fairly reputable performance. However, due to sound waves colliding against the baffles stationed in the housing, the baffles and the housing unit are prone to unwanted vibrations when the speaker is driven at high levels, thus diminishing the high fidelity capability.
In U.S. Pat. Nos. 4,655,315 to Saville and 4,930,596 to Saiki et al., a loudspeaker is housed in a specially configured sound collecting tube to modify the frequency response. The efficiency of the speaker, however, in such an arrangement suffers because sound travels through a restricted opening. Furthermore, because of the frequency response modification, colored or distorted sound becomes apparent, whereas in the present invention, a freely aspirated sound collecting tube is not designed to color sound. Thus, sound generated from the loudspeaker is heard without the addition of unwanted sound colorization.